During the last several months, we have continued our efforts to investigate the mismatch repair gene, hMSH2, as a molecular marker for urothelial malignancies. The assay utilizes bladder washes from individuals undergoing diagnostic or treatment cystoscopy and correlates the presence or absence of hMSH2 with pathological findings, particularly the presence of a tumor. We have found that upper tract lesions of the kidney have increased expression of this important gene. We will continue to refine and define the assay such that it offers the highest sensitivity and specificity for detection of genitourinary lesions. In addition, we hope to utilize this test to identify individuals with tumors which do not express MSH2. These patients may offer important insight as to the treatment of tumors which have become refractory to local treatment.